What could this be? And what was it used for?

It’s a hand clamp/vise.

Works great for small parts that are hard to hold. You could use it with the belt sander for example.

Here’s one that Micro-Mark sells:

http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=84018

-- Gary, East TX -- The longest journey begins with a single step.

Well, Gary took the fun out of the game, I was going to say it looks like a mid 1800’s dentist kit. =)

-- Thuan

That looks like a nice brace and bit /hand drill set though. I would use it.

-- Urban logger, http://nelsonwoodworks.biz/

Looks like the little hand vise might have a hollow handle. Try to twist the end off and see if there’s anything inside.

-- Paul, Texas

Looks like it could also be an extra handle for the brace and bit.

Gary and Paul got it….lol
The handle contains very old but in great shape….chisle type bits. They used it for carving.
Jim

-- A duck that brags on his own pond, soon swims alone.

first one I’ve ever seen. If I come across one now I’ll know not to throw it back into the pile thinking it is a broken piece off of something else…lol

-- JJohn

Looks like some torture implement. A thumb screw perhaps. LOL

-- Grumpy - "Always look on the bright side of life"- Monty Python